# Coordination Compounds VVI Questions

## Coordination Compounds Subjective Questions

Q.1.Find the oxidation number of Cu in the complex ion : [Cu(NH3)4]2+

Ans – Suppose the oxidation number of Cu in this complex is x. Since, NH3 is a neutral molecule. The sum of oxidation number of all the species present in it should be equal to the charge present on the ion, Hence,

x + 4 * 0 = + 2

x = + 2

Thus, the oxidation number of Cu in the complex ion is +2.

Q.2. What is coordination number ?

Ans – The total number ligands to which the metal is bounded through a Co-ordinate bond in the given complex is known as Co-ordination number. e.g.

[Co(NH3)6]3+ has co-ordination number = 6 .

[Ni(CO)4] has co-ordination number = 4

Q.3. Write IUPAC name of : [Cu(NH3)4]Cl2

Ans – [Cu(NH3)4]Cl2

x + 0 * 4 + (-1) * 2 = 0

x = 2

Tetraammine copper (II) chloride.

Q.4. Write IUPAC name of : K2[Fe(CN)6]

Ans – Potassium tetra cyanonickelate.

## Coordination Compounds Objective Questions

Q.1. K3[Fe(CN)6] is a –

(a) Double salt

(b) Complex compund

(c) Acidic salt

(d) Common salt

Ans – (b) Complex compound

Q.2. IUPAC name of H2[PtCl6] is –

(a) Hydrogen hexachloro platinate (IV)

(b) Hydrogen hexachloro platinate (II)

(c) Hydrogen hexa chlorido Pt (IV)

(d) Hydrogen hexa chlorido Pt (II)

Ans – (a) Hydrogen hexachloro platinate (IV)

Q.3. Mercuric chloride reacts with ammonia gas and forms white precipitate. The molecular formula of white precipitate is –

(a) HCl . 2NH3

(b) Hg(NH3)2Cl2

(c) Hg(NH2)Cl2

(d) Hg(NH2)Cl

Ans – (b) Hg(NH3)Cl2

Q.4. What is the coordination number of Cr in [K3Cr(OX)3]

(a) 6

(b) 5

(c) 4

(d) 3

Ans – (a) 6

Q.5. The EAN of cobalt in the complex ion [Co(en)2Cl2]⊕ is –

(a) 27

(b) 36

(c) 33

(d) 35

Ans – (b) 36

Q.6. K4[Fe(CN)6] is a/an –

(a) Double salt

(b) Complex salt

(c) Acid

(d) Base

Ans – (b) Complex salt

Q.7. What is the coordination number of sodium in sodium oxide (Na2O) ?

(a) 6

(b) 4

(c) 8

(d) 2

Ans – (b) 4

Q.8. The oxidation state of nickel in [Ni(CO)4] is –

(a) 4

(b) 0

(c) 2

(d) 3

Ans – (b) 0

Q.9. The number of possible isomers for the complex [Co(C2O4)2(NH3)2] is –

(a) 1

(b) 2

(c) 3

(d) 4

Ans – (c) 3

Q.10. The oxidation state of nickel in [Ni(CO)4] is –

(a) 1

(b) 0

(c) 2

(d) 3

Ans – (b) 0